Just like Hillary Rodham Clinton , members of Congress can use personal email addresses to conduct congressional business. But those communications are not immune to FBI search.

On Wednesday, a federal appeals court opinion shed light on Rep. Chaka Fattah's fight to squash a search warrant seeking data from his Gmail account. The Pennsylvania Democrat, indicted July 29 for alleged racketeering conspiracy, bribery and wire fraud, objected to turning over some emails sought in a grand jury subpoena, arguing disclosure would violate his constitutional protections.

Several months later, a judge has issued a search warrant authorizing the FBI to dig for evidence of criminal activity dating back to Jan. 1, 2008. Fattah claimed he used his Gmail account to communicate with fellow members of Congress about legislative business, send schedules and agendas for committee meetings and to communicate with his staff regarding congressional matters. Fattah also claimed he used the Gmail account to interact with his lawyers.

But the U.S. District Court for the Eastern District of Pennsylvania rejected his argument that handing over the emails would violate the Speech or Debate Clause, or violate attorney-client privilege. It also denied a request from House attorneys that the court modify the warrant and allow Fattah access to the requested records.

"Creating special protections for a Congressman's private email account would encourage corrupt legislators and their aides to make incriminating communications through private emails, knowing that they will be disclosed only with the authors approval," the court opined in the sealed case, according to the appellate decision.

The Speech or Debate Clause, a protection Congress is granted to shield legislative work from prosecutors, secures a privilege of "non-use, rather than of non-disclosure," the 32-page document states, concluding that the appeals court lacks jurisdiction to consider the argument, but the precedent is clear. In other words, the executive branch can look at the records, but it cannot use them as evidence.

"The crux of the Clause is to 'prevent intimidation by the executive and accountability [for legislative acts] before a possibly hostile judiciary.' It is clear that the purpose, however, has never been to shelter a Member from potential criminal responsibility," the opinion states.

Prosecutors argued on Aug. 26 the request should be denied. They also stated Fattah misunderstands the terms of the current arrangement, which they claim bars him from contacting any potential witnesses, "whether a lawyer is present for the conversation or not."

Since the indictment, Fattah has asserted his innocence in a 4-minute YouTube video and suggested the charges are part of an "attack my family" aimed at tarnishing his 30-year career in public service. Those statements give prosecutors reason to believe that Fattah will argue the charges against him are politically-motivated and try to introduce evidence in favor of jury nullification.

On Sept. 21, the judge is set to consider a motion from prosecutors that would prohibit Fattah's legal team from introducing evidence of "purported prior good acts" to the jury.